Improvement in valve-o-ear of steam-engotes



DA vin c. STA RKEv,-

or Naw voxan, N. v.

Letters Patent No. 104,224, dated .lune 14, 14870.

IMPROVEMENT IN VALVE-GEAR OE' STEAM-EN GINES.

The schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern:

Be it known that I, DAVID STARKEY, of the city and State of New York,have invented an Improvement in Steam-Engines', and the following isportion where the Imovement should be-thc most `rapid.

Instead of employing an eccentric or a cam I make .use of a linkactuated by the lateral movement ot' the pitman or connecting-rod.

rlhis lateral motion is the most rapid as thc crank passes the deadcenters; hence, the valve is moved with rapidity in opening. and closingthe ports, and remains almost stationary while the. piston is moving inthe middle portions ot' tbc stroke.

I non'nt the piston upon a rod that passes through both heads, so as toform guides, and the cross-head is behind the cylinder, and from thisthe connecting- `rods pass at the sides of the steam-cylinder to asecond cross-head and connection to thecrank.

. In the drawingy Figure 1 is a plan otiny improved engine, and

Figure 2 is an elevation with the valve in section.

le is the steam-cylinder.

l), the piston-rod, connected to the cross-head c, and from the ends ot'said cross-head the two pitmen or connecting-rods fl d pass along at thesides o f the cylinder a to the cross-head e,'frou1 which the rod fconnects to the crank g of the main shaft It. Y

The piston-rod b passes entirely through the cylinder c, so as to form aguide and dispense with the slides usually Yprovided for the cross-head.

By using the second cross-head c and rod f, but one crank is required.

Above the cylinder c is the steam-chest lr, containing the cylindricalvalve i, in which are steam-ways 2 2, and exhaust-way 3, and in thechest are the ports 4 4, to the steam-cylinder and the exhaust-port 5.

The valve Ii is upon the stem l that passes through a stuffing-box, andhas at the end an arm, m, from which the link n passes to the pitman orconnectingrod d. s

'lhe parts are united by joints, so as to allow of la free motion, andthe connection between the arm m and link n| should be adjustable, sothat the proper position and movement may be obtained.

It will now be understood that when the crank g is near the quarterpoint, and the piston of the engine in the middle portion of its stroke,there .is but little movement given to" th'e valve, because there is butlittle lateral motion to the rods d, but, asrthe crank turns the center,the connecting-rods rcceivea rapid lateral motion, which motion istransmittedy by the link aand arm m to the valve i to' open one exhaustand the opposite steam-port with rapidity.

This construction of mechanism is very simple, and f the rapid motion isgiven to the -valve at the proper portion of the stroke, and 'but littlemotion during 'that part of the stroke where the steam and exhaust- Iports require to be fully open.

In consequence ofthe arrangement of the connecting-rods, cross-heads andpistou-rods, the engine is very compact, and there is no undue strain orwear upon any of the parts.

I do not claim a three-way cock or plug forming the valve forasteam-engine.

What I claim as my invention is- 1. A connection between the pit-man orconnectinglrod and the valve, substantially as s et florth,I so that thelateral movement of the -said connecting-rod iinparts a movement to thevalve, as specified.

2.'The cylindrical valve i, containing the steam and exhaust-ways, incombination with the arm in, link n, 'and pitman, arranged and actingsubstantially as set forth. v

3'. The arrangement of the connecting-rods d df,

Witnesses z 'HAROLD SEnnnLL, GEO. T. PINGKNEY.

